Alright, I got coaxed into making a post. ^^ but here are some of my opinions about this subject. Please keep in mind these are just my views and I am waiting to watch this turn into another Pudding E-Peen contest in the very near future.
HNM
Your basic goals for HNMs in my opinion should be 320 Elemental magic / 140 INT to ensure decent dmg and minimal resists. You can make up for lacking in either with the correct support jobs (i.e. BRDs for INT, CORs for Magic Acc)
AF2 vs. Others
Pants = Win!
With a bonus that is active on the corresponding element, the bonus is amazing. Basically, even casting Stone on Earthday for the same damage as an unmerited Fire or Wind for a lot less MP make them the obvious winner.
The rest are all situational imo.
Hands = DRK magic macro
Body = Running around refresh
Feet = Good solo piece
Head = Pushing up Ele for HNMs (substituted with Elite easily)
Belt = Gimme!
Mahatma vs Jet
This is a preference call for me. Basically it boils down to +1INT/MND vs 15 MP and no negative stats. At end-game, the loss of 1 INT < +15 MP and no negative effects for me. The +MND does help your Stoneskin, but if you have an enhancing torque and a decent MND set your stoneskin (Water Staff > Earth Staff here) should be maxed at 350 already. P.S. if /RDM, dont forget to put that enhancing gear on for Phlanax ^^
Pudding Damage
Dave, I am pretty sure I have seen you do more than that but would have to look up the parses. These are also pre 5/5 INT for me, but with max ele, pot, and AMII. I will have to go back and try to break that magical 2.5k soon.^^
The information below is with optimal setup for me (Thundersday, Obi, HQ Staff, Uggy, Spirit Lantern, Burn, and unfortunately no HQ weskit/Hands/Novio). Also, I included the full relative portion of the screenshot, so any manipulation could be easily noticed and found.